 class StudentXW extends Student {
     private String duty;
     public StudentXW(String id, String name, double Englishscore, double Mathscore, double Computerscore, String duty) {
         super(id, name, Englishscore, Mathscore, Computerscore);
         this.duty = duty;
     }
     public double testscore() {
         return super.testscore() + 3;
     }
     public String toString() {
         return super.toString() + "duty:" + duty;
     }
 }